1. Field of the Disclosure
This disclosure relates to an electrostatographic printing system that employs an imaging device, and more particularly, to cleaning residual toner from a charge retentive surface of the imaging device.
2. Description of Related Art
Electrostatographic machines including printers and copiers form a latent image on the surface of photosensitive material which is identical with an original image, brings toner-dispersed developer into contact with the surface of the photosensitive material, and sticks toner particles only onto the latent image with electrostatic force to form a copied image on a copy sheet. Thus, a toner image is produced in conformity with the original image. The toner image is then transferred to a substrate and the image affixed thereto to form a permanent record of the image to be produced. Although a preponderance of the toner forming the image is transferred to the substrate during transfer, some toner invariably remains on the charge retentive surface of the photosensitive material, it being held thereto by relatively high electrostatic and/or mechanical forces. Additionally, paper fibers, toner additives, kaolins and other debris have a tendency to be attracted to the charge retentive surface. It is essential for optimal imaging that the toner and debris remaining on the charge retentive surface be cleaned therefrom for quality images to be produced by the machines.
“Blade cleaning” is a technique for removing toner and debris from a photoreceptor. In a typical application as disclosed in U.S. Pat. No. 5,208,639 which is included herein by reference, a relatively thin elastomeric blade member is supported adjacent to and transversely across the photoreceptor surface with a blade edge that chisels or wipes toner from the surface. Toner accumulating adjacent to the blade is transported away from the blade area by a toner transport arrangement or by gravity. Blade cleaning is advantageous over other cleaning systems due to its low cost, small cleaner unit size, low power requirements, and simplicity. However, conventional blade cleaning systems suffer from short life due to early, random failures. Attempts to identify blade materials that possess better reliability and enable dramatic life improvements have not been successful. Introduction of additional blade lubrication can significantly improve blade reliability and life, but adverse interactions with other xerographic systems frequently occur. The introduction of photoreceptor surface coatings has improved photoreceptor life, but these coatings typically result in far higher blade wear rates. Improvements from the introduction of additional lubrication are typically more than offset by the use of coated photoreceptors.
Cleaning blades perform best and last the longest when they are uniformly loaded to the desired blade load. Part tolerances typically require that the blade be loaded higher than desired in order to guarantee that the minimum blade load is larger than that required for better cleaning over the expected life of the blade. The higher blade load increases blade wear and shortens blade life. The cleaning blade, blade holder and blade mounting surfaces are held to high tolerances at increased cost to minimize the variation in blade interference to the photoreceptor. Extra cost is incurred by requiring inspection of the resulting blade load to insure that part manufacture and assembly maintain process control. In some cases each individual blade is set up using optical devices to achieve the desired blade interference. Control of blade load and its uniformity adds cost and reduces life of cleaning blade systems.
Accordingly, there is an unmet need for systems and/or methods that facilitate overcoming the aforementioned deficiencies.